//Name:   get_most_recent_message_description
//Description:   Returns the description of the most recent message
//Type:   Task / Custom Field Value

if (task.getMessages()!=null){
  Object list = task.getMessages();
  Collections.reverse(list);
  int j=task.getMessageCount();
  if (j>0){
    Object message = list.get(j-1);
    if (message.getDescription()!=null){
      return message.getDescription();
    }
  }
}

return null;